ATLANTA — Three weeks had passed since Sandy Alderson last accompanied the Mets on a road trip. A pair of losses in San Francisco had knocked the defending National League champions to two games below the .500 mark, forcing the general manager to answer questions about the status of manager Terry Collins.

Since then, the Mets have become unrecognizable.

On Friday afternoon, Alderson lauded the once-embattled Collins for his steady hand through rough waters. Then he watched the Mets record their 15th victory in 19 games as they rallied to beat the Braves, 6-4, in a victory that captured what has been a season-altering surge.

“The team has played well,” Alderson said, offering a statement that rings more true as the Mets get healthier by the day.

Curtis Granderson lined a tying RBI single in the eighth ahead of a pinch-hit double by Kelly Johnson that secured the lead. With that, the Mets roared back from a 4-0 deficit.

“He’s been doing it for two years,” Collins said of Johnson, a key cog in last year’s pennant run who was reacquired from the Braves in a trade.

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The Mets (75-66) earned their sixth straight win and remained a half-game ahead of the Cardinals for the second wild card. They remained a half-game behind the Giants for the first wild card, as San Francisco beat Arizona in 12 innings, 7-6, in a game that ended after 3 a.m. EDT.

Earlier, Granderson homered for the fourth straight game. His two-run shot in the sixth ended Julio Teheran’s 29-inning scoreless streak against the Mets.

Jeurys Familia earned his 48th save, striking out Tyler Flowers on three pitches with two runners on base.

Bartolo Colon starts against the Braves on Saturday night in place of Seth Lugo, who was bumped back to Sunday as he recovers from a blister issue. Like Robert Gsellman, who allowed four runs and seven hits in five innings against the Braves on Friday night, Lugo has been an unexpected linchpin in a rotation battered by injuries.

Alderson has since adopted a hard line, refusing to discuss the contingent of players who have been sidelined. “The players that have gotten us here are the players that are healthy, the players that have performed,” he said. “And it doesn’t do the team any good, it doesn’t do anybody a service to constantly talk about when, if, how long certain players are going to come back.”

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Nevertheless, the Mets may only be getting healthier.

As they try to clinch a second consecutive playoff spot for the second time in franchise history, Jacob deGrom (sore forearm) played catch on flat ground a day ahead of Steven Matz, who is scheduled to throw off a mound in Port St. Lucie, Florida, his first bullpen session since he was sidelined with a left shoulder impingement.

“I really, truly think that they both might be part of this here real soon,” Collins said.

Centerfielder Juan Lagares also is progressing from thumb surgery. He might return in time to give them a Gold Glove late-game defender. First baseman Lucas Duda will take live batting practice Saturday after missing much of the season with a stress fracture in his back.

But Alderson insisted that the focus must remain on the players on the field. “We have the players we have,” he said, sounding a far different tone than he did three weeks ago. “And they’ve done a great job.”